


A Stubbornly Persistent Illusion

by nahnahnahnah



Category: Bleach
Genre: Alternate Universe - Canon Divergence, Canon - Manga, Established Relationship, M/M, Other Additional Tags to Be Added, Time Travel, Time Travel Fix-It, UraIchi Week
Language: English
Status: In-Progress
Published: 2020-05-25
Updated: 2020-05-25
Packaged: 2021-03-03 01:14:41
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,821
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24376357
Author URL: https://archiveofourown.org/users/nahnahnahnah/pseuds/nahnahnahnah
Summary: Years after Yhwach was defeated, Aizen fulfills everyone's worst fears by breaking out of the Muken, stronger than ever. In a desperate act to save them all from a losing war, Kisuke and Ichigo go back in time to kill him before he becomes a threat.But they can never return, and in order to carry on with their lives in the past, they're going to have to gain the trust of everyone around them while trying to mitigate the worst of Aizen's actions until they can manage to stop him.It really doesn't help that Ichigo can't help trying to make the lives of the people he lovesbetter.
Relationships: Kurosaki Ichigo/Urahara Kisuke
Comments: 24
Kudos: 166
Collections: UraIchi Week 2020





	A Stubbornly Persistent Illusion

**Summary for the Chapter:**

> Shunsui brings the most hopeful news the Gotei 13 has heard since the start of their second war against Aizen: the possibility of time travel to a time when Aizen can actually be killed. A devastated Ichigo and worried Kisuke are chosen to take on the mission.

**Notes for the Chapter:**

> The title comes from an Einstein quote written in a letter of condolence to the family of a friend of his that had passed away: "People like us, who believe in physics, know that the distinction between past, present and future is only a stubbornly persistent illusion."

They didn’t line up the way they used to in Captains’ Meetings.

Kisuke wasn’t entirely sure when _that_ had happened; Ichigo had taken to attending the odd meeting over the years, but he hadn’t been to one since he’d begged for Soul Society to restore Ichigo’s power.

He wondered how many they’d lost before the old habits became too painful.

Well, for most of them, anyway. Byakuya-san was still standing at attention in what would’ve been his place in line. But even the Captain-Commander wasn’t holding himself to such a standard.

He looked like he might just be too weary to attempt it.

But he still stood at the front of the room, even if he seemed more stooped than Yamamoto ever had. Okikiba-fukutaichou stood at his shoulder, his eyes downcast.

Kotetsu-taichou and Kotetsu-fukutaichou were standing slightly off kilter from their normal positions; possibly they had wanted to make a showing of normality, but likely they didn’t want to get too close to Byakuya-san. Kisuke personally might’ve found Zaraki-san’s looming presence over them a bit more off-putting, if he were the type of person to find things off-putting, but from what Ichigo had said they might be used to it by now.

Not many had dared to get too close to Byakuya-san after his sister and lieutenant’s bodies had been found.

Shinji was a bit removed from the others, talking softly to—or maybe _at_ —Kensei.

No, that was an unfair assessment. Kensei looked as invested and focused as he ever did these days. And he was more of a participant than Lisa, certainly; she stood apart from them, and while her body was oriented _toward_ them she wasn’t looking _at_ them.

She also hadn’t looked once at the front of the room, at Shunsui, since she’d entered.

Kira-fukutaichou was standing against the wall to the side; he wasn’t talking to anyone. He didn’t talk much at all since he’d been taken, since they found out the immortality Mayuri granted him had seemed to _stick_.

Speaking of, the Twelfth Division was notable for their absence. Mayuri and Akon were still alive—he’d certainly have found out about it if it were otherwise—so this could only be voluntary.

Kisuke kept part of his attention on the various interplays happening; it was more habit at this point than anything, but it was always good to know where it would be most expedient to apply pressure if necessary.

Another part of his attention was, as it always had been when they were in proximity, on Yoruichi. She’d braced herself against the back wall, a few feet away from where he stood himself. He wondered idly whether she’d taken official control of the Onmitsukidou yet, or if she was still pretending she was standing in for Yuushirou.

And part of his attention was on the newcomer, standing behind Okikiba-fukutaichou with his head bowed and eyes lowered. A distant part of his mind was wondering whether they were finally filling one of the gaps in the command structure. The man didn’t quite look like captain material, but Kisuke was hardly one to judge. He just seemed…average. Brown hair, brown eyes, average height, average build, which meant he stood out in a room of extraordinary people, though no one else was taking much notice of him.

The majority of his attention was of course on Ichigo, as it should be and had been for the last few years.

Ichigo, who stood next to him, close enough that their sleeves brushed. Ichigo, whose shoulders were stiff with tension. Ichigo, whose face was drawn and pale, jaw set, eyes like flint.

He’d changed in the weeks since the attack; Kisuke had expected as much. But.

He couldn’t help but worry about him.

Shunsui was calling the meeting to order.

“Thank you all for assembling so promptly,” he said. He wasn’t smiling. He didn’t smile much since Ise-fukutaichou had gone missing. “There’s been a recent development that I think will be a turning point in this war.”

Everyone was watching him now; in the past, there may have been comments, whether sarcastic or encouraging. Now there was silence. They’d lost too many, and fought for too long.

“Watanabe-kun has recently achieved Bankai,” he continued, gesturing to the stranger behind Okikiba-fukutaichou. “His zanpakutou’s special ability is apparently time travel.”

 _That_ caused a stir; even Ichigo openly showed interest, looking over at the Shinigami in question.

He stood firm under the scrutiny; Kisuke observed that distantly, more focused now on the way Ichigo’s face was shifting. His jaw clenched harder, and his eyes narrowed. It was more expression than he’d shown in days.

Watanabe-san stepped forward. His brows were furrowed and his jaw was tense; Kisuke thought he might be nervous. He seemed the type to express it like that. When he spoke, his voice was level. “My Bankai allows me to send a person back to a moment that corresponds to a point in their own life at a time of heightened emotion. The stronger the emotion is, the easier it is to pinpoint the correct moment and the earlier I am able to send the traveler. At this point, my strength suffices to send one other person; this may increase with training, but I cannot guarantee it.”

The stir of interest became a buzz of shocked conversation, the likes of which hadn’t happened in months.

“What happens to the timeline?” Kisuke asked. He’d not had time for scientific explorations lately; despite his preoccupation with Ichigo, this sparked his interest.

Watanabe-san gave him a nod that bordered on a bow. Yes, definitely nervous. “This timeline as it exists will be destroyed.” Everyone went silent once more, but this was a waiting silence. A silence that might develop teeth. “There is no hope of return for the traveler or travelers. There should be no effect on their memories; it will be as if they have lived two lives.”

“Wait,” Yoruichi said, eyes narrowing, glancing halfway at Ichigo as she spoke. “If you’ve got a second person, do they also have to be alive at the point you send them back?”

Watanabe-san blinked. “That shouldn’t matter,” he said. “The traveler and whatever companion they have are sent back bodily.”

That caused another little stir around the room; eyes flicked over to them, to Ichigo, and then away.

“That would mean you’d have…time-travel doubles running around?” Shinji confirmed, and Watanabe-san nodded.

“Is there a catch? Do you have to never encounter your double, or anything like that?” Kensei demanded almost angrily. He’d gotten harsher since Hisagi-fukutaichou’s body had been found.

“No, it’s a stable timeline. There’s no danger of paradox or anything of the like,” said Watanabe-san. “The traveler simply…is placed in the past, and goes on from there.”

Shunsui stepped forward again, regaining the attention of the room. “This may be the key in defeating Aizen at last. We’ll need to act quickly before he can attack Watanabe-kun, but as I understand it there’s no way for him to fully counter this ability once it’s activated. Aizen will be erased with the rest of this timeline.”

“I’ll guard him,” Ichigo said, and everyone in the room turned to look back at him. “Aizen doesn’t come near me.” It was true; he’d avoided direct confrontation with Ichigo since he’d broken out of the Muken, at least so far.

“So,” Shunsui said heavily, gazing around the room, “The question is, which of us is going back?”

Ichigo was the obvious choice. That much, judging from the surreptitious glances sent his way and Yoruichi’s earlier question, was clear to everyone. He was the most powerful of them all, some by an order of magnitude, and he was probably right that Aizen was refusing to meet him in open battle because he was the greatest threat against him.

An Aizen not on guard against him, an Aizen before the Muken, hopefully even an Aizen before the Hougyoku, depending on when they managed to go, would be child’s play for him to defeat. And there was Yhwach to consider as well; defeating Aizen before he helped with that fight would mean Ichigo’s strength and experience would be needed to defeat _him_. Really, Ichigo nearly _had_ to go.

Kisuke would just have to make the case for why _he_ should be the one to accompany Ichigo.

“It ought to be Ichigo and Kisuke,” Shinji said before he even opened his mouth. He looked flatly around at all of them. “I mean, we all agree it’s got to be Ichigo, right?”

There were some nods; mostly it was stony looks, but nobody raised an objection. Ichigo stood next to Kisuke and didn’t react, but his eyes had a glint in them Kisuke had been beginning to fear wouldn’t be coming back. He reached out without looking and took Kisuke’s hand; Kisuke squeezed back, more heartened than he liked to admit by the gesture.

“Aizen himself acknowledged that Kisuke’s smarter than him. And whoever’s sent back is going to have to be able to anticipate the effects of whatever changes they make.” Shinji shrugged. “Kisuke’s the best suited for that.”

Shinji belied his logical argument with the look he shot between Kisuke and Ichigo. Ah. Sentiment was playing a role, but in fairness _sentiment_ was a large part of why Kisuke wanted to be the one to go with Ichigo. And the arguments were sound.

“I’m always willing to do whatever benefits the Gotei,” Kisuke said, and he was, but he was absolutely certain everyone present knew it was more than that. For one thing, he still hadn’t let go of Ichigo’s hand.

“I have no objections,” Byakuya-san said. The deaths of the people closest to him had left him colder and more withdrawn than ever; Ichigo had been the only one whose presence he stood with any grace afterward. The fact that he was willing to speak carried weight; slowly the same sentiment spread around the room.

“Well than, Watanabe-kun, when can we start?” Shunsui asked with a shadow of a smile.

~*~

Watanabe-san said he needed time to mentally prepare and gather his strength; they next day, he said, would suffice.

True to his word, Ichigo brought him back to Kuukaku’s house with them.

Kuukaku had taken them in…after. After Ichigo was left with no other family and nothing for him in the World of the Living.

Aside from Kisuke, of course, but Kisuke was more than willing to relocate back to Soul Society if it would help Ichigo escape the memories.

He hadn’t been sure, after the attack, whether Ichigo would welcome his presence. He’d been closer than Ichigo, and he hadn’t been able to protect them.

He would have given Ichigo whatever space he needed—he would have given Ichigo _whatever_ he needed, full stop.

Ichigo preferred to be close to him.

That meant that their futons were pushed together at night, though that hadn’t been much of a change from how things had been the past few months, and it meant that Ichigo held him as they lay together.

He wasn’t quite sure if it gave Ichigo comfort, knowing he could physically keep Kisuke close, or if he’d just gotten fed up with Kisuke’s awkward hovering that first night, but he kept pulling Kisuke in every night.

“Do you want to go?” he asked him softly in the dark that night, the words half-muffled by Ichigo’s shoulder.

Ichigo was silent aside from a slight hitch in his breath.

“I thought you would,” Kisuke went on, “And I think we are the best choice. But if you don’t want to go, we have time.”

“Time for what?” Ichigo asked. “Time for Aizen to slowly pick off everyone else the two of us care about, until we’re the only ones left?”

Kisuke moved his head slightly, looking up at Ichigo’s profile. Even with his night vision, it was difficult to make out his features in the thin light filtering in from the hall.

They hadn’t spoken about that yet; both were aware Aizen had a fixation on the two of them, acknowledged them in a way he rarely showed to others.

“I’m sorry,” Kisuke said, soft and miserable. “I should have known—”

“We did know,” Ichigo interrupted him, far gentler than Kisuke expected or deserved. He brought a hand up, touching Kisuke’s cheek softly. “We knew what he was capable of. We all knew what he was planning. My dad just…wasn’t enough to protect them.” Ichigo was silent for a moment, and Kisuke barely dared to breathe. He remembered those terrible hours after Ichigo had found them; he never wanted to see the man he loved reduced to that again.

But Ichigo continued. “We…we got overconfident. But you’ve lost people too, Kisuke, and you didn’t blame me for that.” Kisuke closed his eyes for a moment, remembering the way Ururu and Jinta had trailed after Tessai, bickering as they accompanied him on an errand, before they realized how brazen Aizen would and could get. “Aizen’s the one to blame,” Ichigo continued, “and this is a way we can undo the damage he’s done.”

Ichigo’s tone was firmer and rang with more determination than Kisuke had heard from him since the attack. He reached up and pressed his hand to Ichigo’s, turning his face slightly to press a kiss to his palm. He was beyond relieved that Aizen hadn’t managed to finally snuff out his fire entirely.

Ichigo’s hand settled more firmly as he guided Kisuke’s face up and kissed him.

It was a bad angle, so it was little more than their lips brushing against each other, but then Ichigo moved and shifted them onto their sides. Their heads tilted at familiar angles as they deepened the contact.

Kisuke made a soft sound, shifting a little closer, and Ichigo broke the kiss. “I’m sorry,” he said. “I can’t, right now.” He was breathing a little heavier than normal.

Shamefully, it took Kisuke a second to realize what he meant. “Oh,” he said, somewhat nonplussed. “I didn’t…ah, have expectations…”

Ichigo huffed and bowed his head, pressing his forehead to Kisuke’s shoulder. “M still sorry,” he mumbled, tightening his arm around Kisuke’s waist.

Kisuke sighed a little and reached up to stroke Ichigo’s hair.

It was a long time before they fell asleep.

~*~

Kuukaku went with them the next morning, without asking or timidity, as was her way.

Not that they had far to go; apparently, according to a quiet conversation Kisuke’d had with Watanabe-san, his ability could move them in time but not in physical location; Ichigo and Kisuke had decided that no matter when they went back to, it would be best to land somewhere isolated.

And Kuukaku had picked the most isolated places to hole up since the fall of the Kiba.

So word had been sent. Yoruichi reached them first, of course, and seemed more interested in greeting Kuukaku than anything else; Kisuke appreciated the pretense as he carefully edged closer to Ichigo, giving a wide berth to Watanabe-san, who had settled into Jinzen.

“Ready?” he asked, softly enough not to attract attention.

He didn’t bother to ask if he was all right; he knew the answer to that.

Ichigo hummed affirmatively in response, glancing at him. His eyes softened just a touch, just for a moment.

That was of course when Shinji showed up, Kensei close behind. Lisa appeared as well after a moment, as if to pass it off like she’d just happened to show up at the same time as the others.

“Yo,” Shinji said as he walked over, lifting a lackluster hand in greeting. Ichigo nodded, once, and Kisuke smiled.

“Hello, Shinji-san,” he said, not as brightly—or annoyingly—as he might have in the past.

“Made your decision yet on when you’re going back to?” Shinji asked, his tone faux-casual.

“We’ve discussed it,” Kisuke said lightly. “Did you have any thoughts on the matter?”

Shinji glanced back at Kensei and Lisa, neither of whom had made any move to approach. Kensei was watching them, his expression just short of a glare, though Kisuke didn’t take it personally. Lisa faced determinedly off to the side.

“Yeah,” Shinji said when it became clear neither of his companions would be chiming in. “Yeah, we’ve talked about it. And no matter when you choose, we wanted to make sure you knew that the Hollowfication incident should stay as it was.”

Kisuke and Ichigo exchanged a look; if Kisuke wasn’t mistaken, there was a trace of self-satisfaction in Ichigo’s expression. Well, he _had_ been right. Probably it was due.

“If you insist, Shinji-san,” Kisuke said, smiling as ever. That would narrow down their options, too.

He had a murmured discussion with Ichigo as the remaining captains and lieutenants trickled in. There were no signs of Aizen, but everyone looked slightly on edge. Ichigo broke away from his side for the first time in days, if not longer, and went to talk to Zaraki-san. Kisuke busied himself with his own goodbyes; it had been a difficult road, learning to respect Ichigo’s privacy, and he wasn’t about to do anything to damage the trust between them now by trying to listen in on his private conversations, not when they were about to be thrust into a situation that would require them to rely so heavily on one another.

Kisuke turned to Yoruichi and Kuukaku, and was content enough to listen to their complaints about well-meaning but incompetent younger brothers for a time.

At last, though, Shunsui arrived, and Watanabe-san pulled himself to his feet.

Kuukaku turned to him then, and said, “You’d better watch out for my baby cousin, Kisuke.”

It was said with far more good humor than he might’ve expected, but he took it seriously regardless and nodded.

“To the best of my ability, Kuukaku-san.”

Yoruichi rolled her eyes. “I’d tell you to watch out for yourself as well, but I think Ichigo will do a better job of _that_.”

He laughed just a little, and met her gaze. There was nothing left to say between the two of them, but Kuukaku wandered off to pull Ichigo into something almost like a hug and a lot more like a headlock. He didn’t struggle.

Yoruichi gave a little huff of laughter next to him, regaining his attention. “I’m glad you’ll have each other,” she said, and Kisuke smiled at her, more sincerely than he’d smiled at anyone other than Ichigo in months.

“Well, I couldn’t let him go without me,” he said, “and there was no way he wasn’t going. Even if Watanabe-san hadn’t shown up, he probably would’ve found a way.”

Yoruichi gave him a judgmental speaking look that said very clearly it would’ve been Kisuke finding a way for him, but then Shunsui was calling for attention.

“Watanabe-kun, you are prepared?” Shunsui asked, and got a grim nod as the man released his zanpakutou.

He turned to Kisuke and Ichigo next. “Have you decided what moment you wish to go back to?”

Based on what Shinji had said, and what he had discussed with Ichigo… “My sentencing, after the Hollowfication incident.” There were a few glances at that, though no outcry or comments.

Shunsui nodded, and he and the rest of them pulled back a bit at Watanabe-san moved forward. “Good luck. Both of you,” he said, and smiled at them.

Ichigo, wonder of wonders, smiled back.

It was a nice sight to leave on as darkness took the both of them.

~*~

Kisuke opened his eyes and looked around, swallowing down nausea. They were in a deserted field near the woodlands, which had been the plan, but unfortunately that made it a bit difficult to tell whether their scheme had worked or not.

“Are we in the right time?” Ichigo asked, and Kisuke looked over at him, surreptitiously checking him over.

“While I’m flattered you rate my analytical abilities so highly, even I can’t tell the year from the state of the forest,” he replied, and Ichigo scowled at him, of course. “Do you feel all right?”

“I feel fine,” Ichigo replied, and a shadow of concern passed through his eyes. “Do you?”

“Yes, yes, it appears it all worked as it should have,” Kisuke said. “Well. Shall we head to the World of the Living? It’s going to be much easier to see if we made it back there, and much safer to poke around and check.”

“Yeah,” Ichigo said, ripping open a Garganta.

~*~

They landed just outside of Karakura Town, or what would become Karakura Town. Kisuke recognized it, and the few doubts he had settled. He knew this place, and he knew this time.

“We made it,” he said with a slight smile, and Ichigo looked grimly satisfied. “Well then, should we find a place to wait for me and plan how to introduce ourselves?”

“Wait,” Ichigo said. “Before we do, I have to talk to you.”

Kisuke paused. Ichigo sounded…very serious. “Oh?”

“We can’t kill Aizen just yet,” he said.

“No,” Kisuke said slowly, “that was never the plan. We need—or _you_ need—to gain the trust of the Gotei 13 first.”

“Yeah,” Ichigo said, “but the thing is…the thing is I can’t kill him until my parents have met.”

Kisuke stopped, his mind racing. Oh. Oh, that was… “Karin and Yuzu?” he asked softly, and Ichigo’s head bowed. Kisuke couldn’t stand to watch Ichigo like that. He reached over and pulled Ichigo in to lean on his shoulder, wrapping him in a loose embrace; he wasn’t great at this, at offering even physical comfort, but he couldn’t do _nothing_.

“He’s going to hurt people,” Ichigo said softly, even as his own arms went around Kisuke’s waist to return the hug. “He’s going to hurt so many people. But if I can’t make sure they meet and stay together long enough to fall in love…I don’t care if my counterpart never exists, but if _they_ don’t, then this will have been for nothing to me.”

“I know,” Kisuke said softly. “I _know_ , Ichigo. We’ll figure it out somehow. I’ll be Aizen’s shadow if I have to, following him around and fixing whatever damage he causes.”

Ichigo laughed a little, but it sounded far too broken for Kisuke’s liking. “I shouldn’t want to let it happen. My mother nearly died, and my father leaving caused the downfall of the Shiba. But I just…I don’t care. I don’t care enough to stop it.”

“No, you just care more about losing two people you love,” Kisuke said, tightening his arm around Ichigo’s shoulders. “You won’t. We’ll make sure they meet. We’ll make sure they get the chance to fall in love and have a family.”

“ _Thank you_ ,” Ichigo breathed out.

Kisuke simply leaned closer, brushing his cheek against Ichigo’s temple.

Eventually, they broke apart and set off in the direction of civilization.

**Notes for the Chapter:**

> My original idea was oh, having two Kisukes around, think of the shenanigans! And then I decided to just traumatize everyone heavily to lead to them being willing to do this at all. So I'm hoping there will be eventual shenanigans.
> 
> This is my first fic in this fandom that I'm actually editing before posting, so I hope you all like it! I don't have a beta, so feel free to let me know if you notice any typos or stupid mistakes.
> 
> I have a pretty long story in mind, and this is more the prologue than anything else. I had lofty aspirations of getting a full rough draft done before UraIchi Week 2020 started, but then, well, current events happened, and I didn't get nearly as much writing done as I wanted. Which is to say this is very much a WIP, to a level that I don't love posting, and I could use the encouragement and motivation. So if you enjoyed it, please tell me!

**Author's Note:**

> Just because I've seen some discourse about comments lately (which, ????), I'm fine with short comments, long comments, "extra kudos" comments, whatever! Please let me know what you think, however you want to do that 😊


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